Communication systems often employ millimeter-wave radio-frequency (RF) signals for various reasons, including the narrow beam characteristic that can be achieved by such signals. Narrow beam characteristics provide for a focused beam that can be precisely directed towards a target antenna and a greater signal reach in a selected direction as a result of a higher gain (in comparison to an omnidirectional RF signal, for example).
Another reason for the use of millimeter-wave RF signals can be attributed to the reduced size of components used for operating on these signals. Such components, which can be readily packaged inside an integrated circuit (IC), can not only include circuit components associated with an RF transmitter, an RF receiver, a signal conditioner, and/or a signal processor, but can also include an RF antenna. Typically, the RF antenna is fabricated upon a substrate of the IC or is integrated into the package and cannot be moved around physically with respect to the package for purposes of orienting the RF antenna in a desired direction when transmitting a millimeter-wave RF. However, this problem can be addressed by using a beam-steering circuit to electronically steer the beam and provide a desired radiation characteristic to the transmitted millimeter-wave RF signal.
Typically, the beam-steering circuit incorporates one or more phase delay elements that are used to selectively change a relative phase characteristic of the millimeter-wave RF signal in order to perform beam steering. Unfortunately, the amount of phase delay provided by a first phase delay element fabricated inside a first IC among a batch of ICs can be different than the amount of phase delay provided by a similar phase delay element fabricated inside another similar IC among the batch of ICs. This can occur due to various factors such as component-to-component variations and manufacturing tolerances. The end result of having such differences, not just in the phase delay elements but in various other elements of RF ICs as well, can lead to an unacceptable level of mismatch in RF beam radiation characteristics from one RF IC to another.
This issue has been traditionally addressed by using testing and/or quality assurance (QA) procedures that require sophisticated test equipment and complex testing techniques. Understandably, many such traditional test procedures can turn out to be quite time consuming and expensive.